Field of the Application
The present application belongs to the technical field of the application of the photoelectronic materials, and relates to a conjugated polymer with hyperbranched structure and specifically to a white-light hyperbranched conjugated polymer based on a red phosphorescent iridium(III) (Ir(III)) complex as a core and its use. The polymer is consisted of red and blue light emitting units connected through conjugated chemical bonds, and can have high-quality white light electroluminescent spectra.
Background of the Application
Electroluminescent devices made of white light polymers have gained wide focus because of its characteristics, such as energy saving, fast response, stable light color, strong environment adaptability, light weight, thin thickness, simple fabrication process and so on, by which they show great potential in lighting and displaying as next lead force of lighting source.
The white light organic electroluminescent materials as a single light-emitting layer can realize white-light emission, the white light organic electroluminescent devices are obtained mainly by introducing different light-emitting groups and utilizing the incomplete energy transfer between the different groups. Poly(9,9-dioctylfluorene) has the advantages of easy modification, wide band gap and high luminous efficiency and so on, and is important in the blue light-emitting materials, which is the first selected material for causing polymers to emit white light. And the organic electroluminescent materials with phosphorescent Ir(III) complexes can simultaneously capture singlet and triplet excitons owing to the introduction of the heavy metal element Ir, by which the material can theoretically achieve 100% internal quantum efficiency. On this basis, the efficiency of white light polymers will be improved extremely because of introducing phosphorescent chromophores to the polymer materials. Good achievements have been gained in this research field of embedding different phosphorescent groups into the main chain of the polymer in the connection manner of side chain or linear chain. However, the synthetic process using the connection manner of side chain is complicated, and the linear chain structure brings about concentration clustering and severe triplet-triplet (T-T) annihilation, thereby resulting in significant roll-off of the current efficiency in the electroluminescent devices, which is not good for the application of the devices.